William ate 2 slices of pie. Nadia ate 5 slices. If there were initially 10 slices, what fraction of the pie is remaining?
Explanation: $\text{fraction of pie eaten} = \dfrac{\text{number of slices remaining}}{\text{number of slices total}}$ Together they ate 7 slices, which leaves 3 out of 10 slices remaining. There is $\dfrac{3}{10}$ of the pie remaining.